Light bulb



FIG. 1 is a front elevational view of a light bulb showing my new design;

FIG. 2 is a rear elevational view thereof; and

FIG. 3 is a left side view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof; and,

FIG. 7 is a perspective view of a light bulb showing my new design.

The broken lines in the figures are for the purposes of illustrating portions of the light bulb, which form no part of the claimed design. 

CLAIM The ornamental design for a light bulb, as shown and described. 